Hi Daren,
I too was bidding on the gearbox case but it got a bit expensive so am going to cast some up. I have a '26 TT and a '29 DT and both cases are faulty. Given the thinness of the cases and the material that Douglas cast them up from welding is extremely hard. Anyway you requested some dimensions on the DT frame. Are you still after them as I can measure mine up if required. Regards, Ian.